{"gene":"TG_217680","gene_symbol":"GRA57","run_date":"2026-09-05T22:31:42","timeline":{"discoveries":[{"year":2023,"finding":"GRA57 forms a heterotrimeric complex with GRA70 and GRA71; this complex enhances parasite survival in IFNγ-activated human foreskin fibroblasts (HFFs), as demonstrated by CRISPR knockout of each component reducing parasite persistence in IFNγ-stimulated human cells.","method":"Targeted CRISPR screening in IFNγ-activated human cells; identification of heterotrimeric complex (GRA57/GRA70/GRA71); gene knockouts with parasite survival readout in HFFs","journal":"PLoS biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — targeted CRISPR screen with functional readout plus complex identification; single lab, two orthogonal approaches (screen + KO validation)","pmids":["37459303"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2023,"finding":"Vacuoles from GRA57, GRA70, and GRA71 knockout strains show reduced host-mediated ubiquitination compared to wild-type, indicating the GRA57-containing complex influences the ubiquitination status of the parasitophorous vacuole; however, this reduced ubiquitination is interpreted as a secondary consequence of complex deletion and not directly linked to IFNγ resistance.","method":"Gene knockout (CRISPR) combined with ubiquitination assay of the parasitophorous vacuole in human cells","journal":"PLoS biology","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct experimental observation in KO parasites with ubiquitination readout; single lab, but the causal interpretation is explicitly flagged as uncertain by authors","pmids":["37459303"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2020,"finding":"GRA57 was identified as a novel bradyzoite-upregulated dense granule protein via proximity biotinylation (MAG1-BirA* bait), indicating it is secreted into the parasitophorous vacuole during the bradyzoite stage.","method":"Proximity biotinylation (BioID) using MAG1-BirA* fusion in bradyzoites; mass spectrometry identification","journal":"PloS one","confidence":"Low","confidence_rationale":"Tier 3 / Weak — single proximity labeling/MS experiment identifying GRA57 as a bradyzoite PV-associated protein; no further mechanistic follow-up on GRA57 specifically in this paper","pmids":["32374791"],"is_preprint":false,"attribution":[{"species":"Toxoplasma gondii","strain":""}]}],"current_model":"GRA57 is a secreted dense granule protein expressed in both tachyzoites and bradyzoites of Toxoplasma gondii that forms a heterotrimeric complex with GRA70 and GRA71 within the parasitophorous vacuole, and this complex is required for parasite survival in IFNγ-activated human cells, with its absence also correlating with reduced host-mediated ubiquitination of the vacuole as a secondary effect."},"narrative":{"mechanistic_narrative":"GRA57 is a secreted dense granule protein of Toxoplasma gondii that acts within the parasitophorous vacuole to promote parasite survival in IFNγ-activated human cells [PMID:37459303]. It functions as part of a heterotrimeric complex with GRA70 and GRA71, and CRISPR knockout of any component reduces parasite persistence in IFNγ-stimulated human foreskin fibroblasts, establishing the complex as a determinant of resistance to human cell-autonomous immunity [PMID:37459303]. Loss of the complex also lowers host-mediated ubiquitination of the vacuole, but this is a secondary consequence of complex deletion rather than the direct basis of IFNγ resistance [PMID:37459303]. GRA57 is expressed across life stages, having been identified as a bradyzoite-upregulated PV protein [PMID:32374791]. Beyond its membership in the GRA57/GRA70/GRA71 complex and its role in IFNγ resistance, the molecular mechanism by which GRA57 protects the vacuole has not been characterized in the available corpus.","teleology":[{"year":2020,"claim":"Before this work it was unknown whether GRA57 was parasite-secreted or where it localized; proximity labeling placed it in the parasitophorous vacuole and defined it as a bradyzoite-upregulated dense granule protein, establishing it as a secreted PV effector candidate.","evidence":"Proximity biotinylation with a MAG1-BirA* bait in bradyzoites followed by mass spectrometry","pmids":["32374791"],"confidence":"Low","gaps":["Single proximity-labeling/MS experiment with no mechanistic follow-up on GRA57","Does not establish any function or interaction partners","Tachyzoite-stage behavior not addressed"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2023,"claim":"The functional role of GRA57 was unresolved; a targeted CRISPR screen in IFNγ-activated human cells showed GRA57 assembles into a heterotrimeric complex with GRA70 and GRA71 that is required for parasite survival, defining a protein module underlying resistance to human cell-autonomous immunity.","evidence":"Targeted CRISPR screening in IFNγ-activated HFFs, complex identification, and individual gene knockouts with a parasite survival readout","pmids":["37459303"],"confidence":"Medium","gaps":["Molecular activity of the complex and the direct effector mechanism protecting the vacuole are unknown","How the complex assembles and localizes within the PV is not defined","Single lab; identity of host targets counteracted by the complex not established"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":2023,"claim":"Whether the complex acts by controlling vacuole ubiquitination was tested; knockout vacuoles showed reduced host-mediated ubiquitination, but this was interpreted as a downstream consequence rather than the direct cause of IFNγ resistance, separating the ubiquitination phenotype from the survival function.","evidence":"CRISPR knockout of complex components combined with ubiquitination assay of the parasitophorous vacuole in human cells","pmids":["37459303"],"confidence":"Medium","gaps":["Causal link between the complex and vacuole ubiquitination not established; authors flag the interpretation as uncertain","The direct effector pathway responsible for IFNγ resistance remains unidentified"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]},{"year":null,"claim":"The molecular mechanism by which the GRA57/GRA70/GRA71 complex protects the parasitophorous vacuole from IFNγ-driven human immunity, and the host targets it engages, remain unknown.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No enzymatic or biochemical activity assigned to GRA57 or the complex","No host binding partners or targeted immune effectors identified","Relationship between vacuole ubiquitination and parasite survival unresolved"],"attribution":[{"species":"Toxoplasma gondii","strain":""}]}],"mechanism_profile":{"molecular_activity":[],"localization":[],"pathway":[],"complexes":["GRA57/GRA70/GRA71 heterotrimeric complex"],"partners":["GRA70","GRA71"],"other_free_text":["Secreted dense granule protein; bradyzoite-upregulated and expressed in tachyzoites [#0, #2]","Complex required for parasite survival in IFNγ-activated human fibroblasts [#0]","Complex deletion reduces host-mediated ubiquitination of the parasitophorous vacuole, interpreted as a secondary effect [#1]"]},"strain_conflicts":[]},"prefetch_data":{},"corpus_meta":[{"pmid":"32374791","id":"PMC_32374791","title":"Proximity biotinylation reveals novel secreted dense granule proteins of Toxoplasma gondii bradyzoites.","date":"2020","source":"PloS one","url":"https://pubmed.ncbi.nlm.nih.gov/32374791","citation_count":36,"is_preprint":false},{"pmid":"37459303","id":"PMC_37459303","title":"A heterotrimeric complex of Toxoplasma proteins promotes parasite survival in interferon gamma-stimulated human cells.","date":"2023","source":"PLoS biology","url":"https://pubmed.ncbi.nlm.nih.gov/37459303","citation_count":24,"is_preprint":false}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":3344,"output_tokens":919,"usd":0.011909,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":5768,"output_tokens":1985,"usd":0.039232,"stage2_stop_reason":"end_turn"},"total_usd":0.051141,"stage1_batch_id":"msgbatch_01XFXJD6iZecXyWn9uU5Qom9","stage2_batch_id":"msgbatch_013GToKgs4AKSCRE4yvueviH","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2023,\n      \"finding\": \"GRA57 forms a heterotrimeric complex with GRA70 and GRA71; this complex enhances parasite survival in IFNγ-activated human foreskin fibroblasts (HFFs), as demonstrated by CRISPR knockout of each component reducing parasite persistence in IFNγ-stimulated human cells.\",\n      \"method\": \"Targeted CRISPR screening in IFNγ-activated human cells; identification of heterotrimeric complex (GRA57/GRA70/GRA71); gene knockouts with parasite survival readout in HFFs\",\n      \"journal\": \"PLoS biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — targeted CRISPR screen with functional readout plus complex identification; single lab, two orthogonal approaches (screen + KO validation)\",\n      \"pmids\": [\"37459303\"],\n      \"is_preprint\": false,\n      \"attribution\": [\n        {\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}\n      ]\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"Vacuoles from GRA57, GRA70, and GRA71 knockout strains show reduced host-mediated ubiquitination compared to wild-type, indicating the GRA57-containing complex influences the ubiquitination status of the parasitophorous vacuole; however, this reduced ubiquitination is interpreted as a secondary consequence of complex deletion and not directly linked to IFNγ resistance.\",\n      \"method\": \"Gene knockout (CRISPR) combined with ubiquitination assay of the parasitophorous vacuole in human cells\",\n      \"journal\": \"PLoS biology\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct experimental observation in KO parasites with ubiquitination readout; single lab, but the causal interpretation is explicitly flagged as uncertain by authors\",\n      \"pmids\": [\"37459303\"],\n      \"is_preprint\": false,\n      \"attribution\": [\n        {\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}\n      ]\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"GRA57 was identified as a novel bradyzoite-upregulated dense granule protein via proximity biotinylation (MAG1-BirA* bait), indicating it is secreted into the parasitophorous vacuole during the bradyzoite stage.\",\n      \"method\": \"Proximity biotinylation (BioID) using MAG1-BirA* fusion in bradyzoites; mass spectrometry identification\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — single proximity labeling/MS experiment identifying GRA57 as a bradyzoite PV-associated protein; no further mechanistic follow-up on GRA57 specifically in this paper\",\n      \"pmids\": [\"32374791\"],\n      \"is_preprint\": false,\n      \"attribution\": [\n        {\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}\n      ]\n    }\n  ],\n  \"current_model\": \"GRA57 is a secreted dense granule protein expressed in both tachyzoites and bradyzoites of Toxoplasma gondii that forms a heterotrimeric complex with GRA70 and GRA71 within the parasitophorous vacuole, and this complex is required for parasite survival in IFNγ-activated human cells, with its absence also correlating with reduced host-mediated ubiquitination of the vacuole as a secondary effect.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"GRA57 is a secreted dense granule protein of Toxoplasma gondii that acts within the parasitophorous vacuole to promote parasite survival in IFNγ-activated human cells [#0]. It functions as part of a heterotrimeric complex with GRA70 and GRA71, and CRISPR knockout of any component reduces parasite persistence in IFNγ-stimulated human foreskin fibroblasts, establishing the complex as a determinant of resistance to human cell-autonomous immunity [#0]. Loss of the complex also lowers host-mediated ubiquitination of the vacuole, but this is a secondary consequence of complex deletion rather than the direct basis of IFNγ resistance [#1]. GRA57 is expressed across life stages, having been identified as a bradyzoite-upregulated PV protein [#2]. Beyond its membership in the GRA57/GRA70/GRA71 complex and its role in IFNγ resistance, the molecular mechanism by which GRA57 protects the vacuole has not been characterized in the available corpus.\",\n  \"teleology\": [\n    {\n      \"year\": 2020,\n      \"claim\": \"Before this work it was unknown whether GRA57 was parasite-secreted or where it localized; proximity labeling placed it in the parasitophorous vacuole and defined it as a bradyzoite-upregulated dense granule protein, establishing it as a secreted PV effector candidate.\",\n      \"evidence\": \"Proximity biotinylation with a MAG1-BirA* bait in bradyzoites followed by mass spectrometry\",\n      \"pmids\": [\"32374791\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\n        \"Single proximity-labeling/MS experiment with no mechanistic follow-up on GRA57\",\n        \"Does not establish any function or interaction partners\",\n        \"Tachyzoite-stage behavior not addressed\"\n      ],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"The functional role of GRA57 was unresolved; a targeted CRISPR screen in IFNγ-activated human cells showed GRA57 assembles into a heterotrimeric complex with GRA70 and GRA71 that is required for parasite survival, defining a protein module underlying resistance to human cell-autonomous immunity.\",\n      \"evidence\": \"Targeted CRISPR screening in IFNγ-activated HFFs, complex identification, and individual gene knockouts with a parasite survival readout\",\n      \"pmids\": [\"37459303\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Molecular activity of the complex and the direct effector mechanism protecting the vacuole are unknown\",\n        \"How the complex assembles and localizes within the PV is not defined\",\n        \"Single lab; identity of host targets counteracted by the complex not established\"\n      ],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Whether the complex acts by controlling vacuole ubiquitination was tested; knockout vacuoles showed reduced host-mediated ubiquitination, but this was interpreted as a downstream consequence rather than the direct cause of IFNγ resistance, separating the ubiquitination phenotype from the survival function.\",\n      \"evidence\": \"CRISPR knockout of complex components combined with ubiquitination assay of the parasitophorous vacuole in human cells\",\n      \"pmids\": [\"37459303\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"Causal link between the complex and vacuole ubiquitination not established; authors flag the interpretation as uncertain\",\n        \"The direct effector pathway responsible for IFNγ resistance remains unidentified\"\n      ],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The molecular mechanism by which the GRA57/GRA70/GRA71 complex protects the parasitophorous vacuole from IFNγ-driven human immunity, and the host targets it engages, remain unknown.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\n        \"No enzymatic or biochemical activity assigned to GRA57 or the complex\",\n        \"No host binding partners or targeted immune effectors identified\",\n        \"Relationship between vacuole ubiquitination and parasite survival unresolved\"\n      ],\n      \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [],\n    \"localization\": [\n      {\"term_id\": \"GO:0020003\", \"supporting_discovery_ids\": [0, 1, 2], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0051607\", \"supporting_discovery_ids\": [0], \"attribution\": [{\"species\": \"Toxoplasma gondii\", \"strain\": \"\"}]}\n    ],\n    \"complexes\": [\"GRA57/GRA70/GRA71 heterotrimeric complex\"],\n    \"partners\": [\"GRA70\", \"GRA71\"],\n    \"other_free_text\": [\n      \"Secreted dense granule protein; bradyzoite-upregulated and expressed in tachyzoites [#0, #2]\",\n      \"Complex required for parasite survival in IFNγ-activated human fibroblasts [#0]\",\n      \"Complex deletion reduces host-mediated ubiquitination of the parasitophorous vacuole, interpreted as a secondary effect [#1]\"\n    ]\n  },\n  \"strain_conflicts\": []\n}\n```","audit_flag":null,"strains":[{"strain":"ME49","gene_id":"TGME49_217680","name":"GRA57","product":"dense granule protein GRA57","uniprot_acc":"S8EUV4","chromosome":"TGME49_chrXII","start_pos":1990590},{"strain":"GT1","gene_id":"TGGT1_217680","name":null,"product":"hypothetical protein","uniprot_acc":null,"chromosome":"TGGT1_chrXII","start_pos":1930956},{"strain":"RH88","gene_id":"TGRH88_059610","name":null,"product":"unspecified product","uniprot_acc":null,"chromosome":"CM023093","start_pos":2002782},{"strain":"VEG","gene_id":"TGVEG_217680","name":null,"product":"hypothetical protein","uniprot_acc":"A0A125YWF7","chromosome":"TGVEG_chrXII","start_pos":1964596}]}